• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.587-595
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• 2015

A by-pass path in wireless sensor networks is the alternative path which be able to forward data when a routing path is being broken. One reason of depleting energy is occurred by the path. The method for solving prior to addressed the problem is proposed. However, this method may deplete radio resource. The best path has advantage that network lifetime of sensor nodes is prolonged; on the contrary, in order to maintain the best path it have to share their information between the entire nodes. In this paper, we propose the best path searching algorithm in the distributed three dimensional sensor networks. Through the neighboring informations sharing in the proposed method, the proposed algorithm can decide the best k-path as well as the extension of network lifetime.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1931-1938
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• 2012

A by-pass path in wireless sensor networks is the alternative path which be able to forward data when a routing path is being broken. One reason of depleting energy is occurred by the path. The method for solving prior to addressed the problem is proposed. However, this method may deplete radio resource. The best path has advantage that network lifetime of sensor nodes is prolonged; on the contrary, in order to maintain the best path it have to share their information between the entire nodes. In this paper, we propose the best path searching algorithm in the distributed three dimensional sensor networks. Through the neighboring informations sharing in the proposed method, the proposed algorithm can decide the best k-path as well as the extension of network lifetime.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1261-1266
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• 2014

Smart shipyard, all of the business of shipyard by using a mobile application, and the rapid spread of smart equipment, the overload of infrastructure due to a variety of mobile services is expected. Because macrocell and femtecell to reduce the overloading of existing infrastructure, additional core network devices have a problem, in this paper, the efficiency of resources than the communication over the existing infrastructure smart shipyard network to improve, to apply the D2D communication technology that can reduce the load on the infrastructure. The proposed routing path plan in accordance with the transfer method and the traffic type of network configuration and D2D equipment navigation and data for applying a smart shipyard. Whether to execute the function to overload traffic in the core network can send to the optimized path was confirmed by using the state transition diagram. Smart shipyard, by applying D2D communication allow efficient traffic handling than conventional communication method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.2
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• pp.65-77
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• 2000

We propose a new formulation by quadratic boolean programming to partition circuits for FPGA based reconfigurable circuit boards, in which the routing topology among IC chips are predetermined. The formulation is to minimize the sum of the wire length by considering the nets passing through IC chips for the interconnections between chips which are not adjacent, in addition to the constraints considered by the previous partition methods. We also describe a heuristic method, which consist of module assignment method to efficiently solve the problem. Experimental results show that our method generates the partitions in which the given constraints are all satisfied for all the benchmark circuits tested. The pin utilization are reduced for the most of the circuits and the total wire length of the routed nets are improved up to 34.7% compared to the previous method.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.2
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• pp.1-10
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• 2010

Mapping virtual process topology to physical processor topology is one of the most important design issues in parallel programming. However, the mapping problem is complicated due to the topology irregularity and routing complexity. This paper proposes a new process mapping scheme called adjacency-based mapping (AM) for irregular cluster systems assuming that the two-dimensional mesh process topology is specified as an interprocess communication pattern. The cluster systems have been studied and developed for many years since they provide high interconnection flexibility, scalability, and expandability which are not attainable in traditional regular networks. The proposed AM tries to map neighboring processes in virtual process topology to adjacent processors in physical processor topology. Simulation study shows that the proposed AM results in better mapping quality and shorter interprocess latency compared to the conventional approaches.

• Convergence Security Journal
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• v.9 no.2
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• pp.71-78
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• 2009

It is very difficult to apply previous security protocols to WSNs(Wireless Sensor Networks) directly because WNSs have resource constrained characteristics such as a low computing ability, power, and a low communication band width. In order to overcome the problem, we proposes a secure group communication scheme applicable to WSNs. The proposed scheme is a combined form of the TEEN(Threshold sensitive Energy Efficient sensor Network protocol) clustering based hierarchical routing protocol and security mechanism, and we assume that WSNs are composed of sensor nodes, cluster headers, and base stations. We use both private key and public key cryptographic algorithms to achieve an enhanced security and an efficient key management. In addition, communications among sensor nodes, cluster headers, and base stations are accomplished by a hierarchical tree architecture to reduce power consumption. Therefore, the proposed scheme in this paper is well suited for WSNs since our design can provide not only a more enhanced security but also a lower power consumption in communications.

• Journal of Navigation and Port Research
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• v.38 no.2
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• pp.171-176
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• 2014

Companies are facing challenges to have high competitiveness because of continuous oil price rising and CO2 emissions regulations. Thus, companies are trying hard to construct effective logistics and operation system to achieve high customer service quality and saving cost. Also the ec-friendly idustrial complex is needed. Busan is in process to construct GILC(Global Industry Logistics City) in west Busan province to achieve high competitiveness and support lack of industrial complex. To construct this kind of logistics industrial complex, it needs logistics system through proper policy and freight transportation co-operation. Especially, efficient management through logistics hierarchy construction in industrial complex is very important for low cost and eco-friendly point of view. Therefore, this paper aims to analyze logistics system and suggest operation model to present logistics complex construction base data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.772-783
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• 2005

In this paper, we propose an effective multicasting protocol in wireless ad-hoc networks. Conventional wired and wireless network multicast protocols do not perform well in wireless ad hoc networks because they were designed without consideration of ad hoc environments such as node mobility, limited bandwidth, high error probability. To solve this problem, some multicasting protocols for ad hoc network have been proposed in the literature. However, these protocols can not provide high packet delivery ratio, low control packet overhead and low expended bandwidth at the same time. Therefore, in this paper, we propose RTMA that improves multicasting performance in wireless ad hoc networks. RTMA calculates its current region from its position information by using GPS in order to make tree among the multicast group nodes in the same region. The proposed region-based tree method is for high packet delivery ratio, low control packet overhead when many senders send data packets. RTMA makes a reliable tree by using speed information to fill a gap of the weak points of the tree structure. When searching the routing path, RTMA selects the reliable path excluding high speed nodes.

• Convergence Security Journal
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• v.14 no.7
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• pp.53-58
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• 2014

MANET can quickly build a network because it is configured with only the mobile node and it is very popular today due to its various application range. However, MANET should solve vulnerable security problem that dynamic topology, limited resources of each nodes, and wireless communication by the frequent movement of nodes have. In this paper, we propose a domain-based distributed cooperative intrusion detection techniques that can perform accurate intrusion detection by reducing overhead. In the proposed intrusion detection techniques, the local detection and global detection is performed after network is divided into certain size. The local detection performs on all the nodes to detect abnormal behavior of the nodes and the global detection performs signature-based attack detection on gateway node. Signature DB managed by the gateway node accomplishes periodic update by configuring neighboring gateway node and honeynet and maintains the reliability of nodes in the domain by the trust management module. The excellent performance is confirmed through comparative experiments of a multi-layer cluster technique and proposed technique in order to confirm intrusion detection performance of the proposed technique.

• Journal of Communications and Networks
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• v.15 no.5
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• pp.504-513
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• 2013

Communication in delay tolerant networks (DTNs) relies on message transport by mobile nodes, and a correct understanding of the node mobility characteristics is therefore crucial to the design of an efficient DTN routing protocol. However, previous work has mainly focused on uncovering all behaviors of node movement, which is not conducive to accurately detecting the specific movement characteristics of a different node. In this paper, we seek to address this problem based on a consideration of social relationships. We first consider social ties from both static and dynamic perspectives. For a static perspective, in addition to certain accidental events, social relations are considered for a long time granularity and tend to be stable over time. For a dynamic perspective, social relations are analyzed in a relatively short time granularity and are likely to change over time. Based on these perspectives, we adopted different efficient approaches to dividing node pairs into two classes, i.e., familiar and unfamiliar pairs. A threshold approach is used for static social ties whereas a density-based aggregation method is used for dynamic social relationships. Extensive experimental results show that both familiar and unfamiliar node pairs have the same inter-contact time distribution, which closely follows a power-law decay up to a certain point, beyond which it begins to exponentially decay. The results also demonstrate that the inter-contact time distribution of familiar pairs decays faster than that of unfamiliar pairs, whether from a static or dynamic perspective. In addition, we also analyze the reason for the difference between the inter-contact time distributions of both unfamiliar and familiar pairs.